In men, the genital component of the excitement phase of the sexual response cycle is manifested by penile erection and scrotal elevation (Kolodny, Masters and Johnson, Textbook of Sexual Medicine, pages 507-508, Little, Brown and Company, Boston, Mass. (1979)). Erection is basically a cardiovascular event that is controlled by the nervous system. The first physical sign of sexual excitation is a change in penile blood flow. Blood flow increases to the penis with sexual excitement and is reduced with sexual inhibition.
Male erectile dysfunction, or impotence, is the inability to achieve or sustain an erection of sufficient rigidity to have sexual intercourse. The causes of impotence are psychological and/or organic (i.e., endocrinologic, neurogenic and vasculogenic). Ten to fifteen percent of male impotence is organic in nature. Organic causes can be from local lesions of the genitalia, endocrine diseases, organic lesions of the nervous system, and/or vasculogenic impotence from reduced blood flow is the most common organic cause usually seen in diabetes. Impotence may be a side effect of a therapeutic drug or associated with a disease such as multiple sclerosis, diabetes and sickle cell anemia, and can be exacerbated by smoking, inadequate diet among other factors. Emotional disturbances, including stress, fatigue or distraction, can also cause impotence.
In the sexual response, neuromuscular events simultaneously increase the amount of blood entering the organ and decrease the rate at which blood is allowed to leave it. Three vascular changes have been indicated in causing erection: shunting of blood into the cavernous spaces, contraction of muscular polsters on deep efferent veins, and vasoconstriction-induced reduction in superficial penile blood flow (G. Conti, Octa. Anat. 14:17 (1952)). As a function of the autonomic nervous system, penile engorgement is controlled by arterial flow through the pudendal artery and the smaller arteries to the penis. The increased arterial flow is accomplished by active dilatation of the arterioles. The process is reversed by the sudden constriction of the arterioles that accompanies ejaculation.
Alteration of blood flow to and from the penis is considered to be the most frequent organic cause of impotence. Vasculogenic impotence results from either arterial occlusion, i.e., the obstruction of adequate blood flow to the penile arteries, or excess venal outflow (cavernovenous leaking).
Treatment of impotence can include counseling directed toward dealing with the male's insecurities and feelings to reduce fears of sexual performance. Treatments for male impotence include surgery, penile prostheses implants including flexible rods and inflatable balloons, drugs such as vasodilators given to induce an erection as an ointment for topical application or a solution for transurethral injection, and external aids such as penile splints to support the penis or constricting rings to alter the blood flow through the penis. A drawback of those systems is their invasiveness, unwanted side effects, cost, inconvenience, and complexity.
Accordingly, an object of the invention is to provide a method of stimulating the male sexual response and inducing penile erection, that is non-invasive and easy to perform. Another object is to induce normal male sexual arousal.